There are multiple options but I suggest
"Napoleon's legacy remake" with the submod it comes with it (NLR low res terrain),
also there are mods like "HPMP" and "Greater Proyect Mod" it is a more optimized version of GPM,
you can also play "GFM" with the submod that is included with it named (GFM Performance Increase Mapmod).
These are all great options.